A rotor shape design of interior PM motor for reducing cogging torque in electric air-conditioning system of HEV

This paper proposes a new design of rotor shape of the interior permanent magnet (IPM) motor used for the electric air-conditioning system of hybrid electric vehicles (HEV). The distribution of the residual magnetic flux density at the air gap was modified by the rotor surface shape and V-type magnet angle. The finite-element method (FEM) was applied to deterimne the optimal shape design of the rotor surface shape and V-type magnet angle because the IPM motor has extreme saturation in the rotor core. The validity of the proposed rotor shape optimization was confirmed by the manufactured IPM rotor core and the performance of the cogging torque was measured.